Measles Cases in Japan See Rapid Uptick

The Yomiuri Shimbun

17:24 JST, April 22, 2026

Measles cases for the year totaled 299 on April 12, the Japan Institute for Health Security said Tuesday. The preliminary figures exceeded the 265 cases reported for all of 2025.

The institute said the week through April 12 saw a record 56 cases. Tokyo had 108 cases, followed by Kanagawa Prefecture with 31, Kagoshima Prefecture with 28 and Chiba and Aichi prefectures with 23 each.

Measles is highly contagious and can be carried through the air. The measles vaccine is the best way to prevent an infection. Of those infected this year, 74% received the vaccine once or not at all, or had an unknown history of vaccination. The measles vaccine can be taken twice at public expense — at age 1 and at preschool age.

Vaccination history and post-infection immunity can be checked at certain medical institutions at one’s own expense.

“If you develop symptoms that you suspect are from a measles infection, such as a high fever or rash, you should check with a medical institution by telephone or similar means, and refrain from using public transportation,” a Health, Labor and Welfare Ministry official said.